1. Field of the Invention
The invention relates to stakes adapted to be driven into a surrounding terrain and, more specifically, to a marker stake such as is used in construction work such as road building.
2. Description of Related Art
The advantages of the stakes of the invention can perhaps be best understood with reference to one prior art field of use, namely as a grading or marker stake. Grading stakes are one type of marker device commonly used in a variety of building and construction industries. Grading stakes are used to indicate the level to which the surrounding terrain must be graded. The stakes are customarily driven to a specified level relative to the existing surface and frequently include a brightly painted top to indicate the existence of the stake top and the level to which the surface ground is to be cut or filled. Other typical uses in the construction industries include topographic surveys of the site to be used in the preparation of plans for a structure and locating in the soil a system of stakes or other markers both in plan and in elevation from which the construction crew can take measurements of earthwork and other measurements for the proper construction of structures. Additionally, temporary stakes or other markers are usually set at the corners of proposed structures, as an approximate guide for beginning the excavation.
Although the top of grading stakes may be initially visible, for example, when the stake top is above the existing ground or is set in a small hand-dug hole, the stakes are frequently covered during the passes of the grader. To improve the visibility of the grading stake, a flag comprising a bundle of brightly colored, polymer filaments is attached to the top end of the stake. In this manner, the colored flag or whiskers will first appear before the top of the stake is reached.
U.S. Pat. No. 3,903,835, entitled GRADE INDICATOR STAKE FLAG HOLDER, issued 9 Sep. 1975, and assigned to the assignee of the present invention shows a marker stake in which the flag or filament bundle is folded at the center and retained by a metal crimp band. The band includes a staple device for attaching the banded filaments to the top of a wooden stake by driving the staple device into the top of the stake.
U.S. Pat. No. 5,501,170, entitled xe2x80x9cGrading Stake With Indicator Flagxe2x80x9d, issued Mar. 26, 1996, to Walsh, purports to avoid the various problems of utilizing an indicator flag that is attached to a wooden grading stake by an attachment means that penetrates the stake. In the Walsh reference, a bundle of colored filaments are fastened at one end to the top end of the stake member by a tape wrap which is wound around the end of the bundle of colored filaments and the top end of the stake member.
U.S. Pat. No. 5,174,237, entitled xe2x80x9cGrade Markerxe2x80x9d, issued Dec. 29, 1992, to Beard shows a grade marker in which the location of the stake is found by the feather that is held by a clip which is driven into the side of the stake.
Despite improvements made in marker stakes of the above type, certain problems continue to exist. The setting of prior art wooden stakes has been time consuming and tiresome in that workers were required to bend over to insert the stakes into the ground. Also, the methods used to drive the stakes into a surrounding terrain were often less than satisfactory. Pounding the top of a wooden stake with a hammer or like tool often caused the stake to split. Also, it was difficult or impossible to drive certain of the prior art stakes into difficult terrains such as rocky ground.
A need exists for a more ergonomic system for installing stakes which is less labor intensive and which is simple in design and operation.
A need exists for an improved marker stake which more securely attaches the filaments of a colored whisker flag to the stake.
A need also exists for a stake adapted to be driven into a surrounding terrain which is made of a synthetic polymeric material which is more durable than existing wooden stake designs.
A need also exists for such a stake which includes a point drive system to facilitate installing the stake in a surrounding terrain by using a simple hand tool as a driver.
The improved stake of the invention includes a stake body which is formed of a durable, light weight material such as a synthetic, polymeric material. The stake body has a bottom pointed end, an intermediate sidewall portion and a top end which terminates in a planar exposed end surface. The stake body has a hollow interior bore which terminates in an end opening in the top end thereof, the interior bore being sized to receive a driving tool for driving the marker stake into the ground. The hollow interior bore terminates in a closed bottom end which is arranged oppositely to the top end opening. The distance between the top end opening and the closed bottom end extends for a predetermined length which places the bottom end in the vacinity of the bottom pointed end of the stake. In this way, the hollow interior extends for more than 50% of the overall length of the stake body and preferably more than about 75% of the overall length of the body. In one embodiment, a filament bundle of stiff, resilient strands form an indicator flag and are attached to the top, planar exposed end surface of the stake body.
In one embodiment of the marker stake version of the invention, the stake body has a cylindrical sidewall portion which is joined to the top end by a frusto-conical wall region. The top, planar exposed end surface has an outer periphery, the outer periphery being of a larger relative diameter than the diameter of the cylindrical sidewall portion of the stake body. In some cases, two filament bundles are attached to the top, planar exposed end surface of the stake body, one of the filament bundles extending upwardly from the exposed end surface to a greater relative height than the other of the filament bundles. The filament bundles can also be colored differently.
In the case of a marker stake, an attachment means is used for attaching the filament bundle to a recess provided in the exposed end surface of the stake body. The preferred attachment means comprises a metal strip which overlays a mid region of the filament bundle when the bundle is received across the recess in the top surface, whereby bending the metal strip by forcing it into the recess on top of the filament strands serves to retain the filament bundle within the recess provided in the top surface of the stake body.
The stake of the invention, with its point drive system, can be driven into the surrounding terrain by using a simple tool comprised of a solid bar carried within a surrounding tube. The surrounding tube terminates in an exposed end region which is sized to be received within and temporarily engaged within the hollow interior bore of the stake body. The solid bar is, in turn, received within the hollow interior of the surrounding tube. Opposite relative movement between the solid bar and the hollow tube serves to exert a downward driving force within the hollow interior bore of the stake body to drive the stake body into the surrounding terrain.
The above as well as additional objects, features, and advantages of the invention will become apparent in the following detailed description.